This disclosure generally relates to an on-board platform with a diagnostics interface for a vehicle. More particularly, this disclosure relates to a reconfigurable in-vehicle platform with a diagnostics interface that includes mounting provisions to maintain overall rigidity, passenger compartment clearance, wireless performance, and enable multi-device installation and communication. The disclosed interface includes a primary diagnostics interface that is received into a vehicle's diagnostic link connector. The primary diagnostics interface includes a connector that can receive expansion modules to enable desired additional and supplemental functions in addition to those provided in the primary diagnostic interface.